Division of Environmental Quality Wellhead Protection Section

Transcription

1 Division of Environmental Quality Wellhead Protection Section 1

2 10 CSR Plugging of Wells Any well which is to be abandoned must be plugged in accordance with these rules. If a well has been determined to present a threat to the groundwater, the division may order that the well be permanently plugged. If a well is in such a state of disrepair that continued use for purposes of obtaining groundwater is impractical and which has not been in use for a period of two (2) years or more, the division may order that the well be permanently plugged. 2

3 Wells abandoned by landowners after August 28, 1991, shall be plugged or cause to be plugged, in accordance with this rule. Landowners may plug their own wells located on property they own or lease, if the wells were intended for use only in single-family houses which are their permanent residences or were intended for use only for farming purposes on their farms, and where the waters that were produced were not intended for use by the public or in any residence other than their own. HAND DUG WELLS AND CISTERNS The early wells and cisterns constructed in Missouri bear little resemblance to their modern counterparts. These early wells were dug and constructed by hand with pick and shovel. 3

4 4

5 Most hand dug wells are from three to six feet in diameter unlike modern wells, they do not contain casing. Brick or field stones were used to line the well, holding the materials in place while allowing water to enter. Their depths are variable; if ample water was encountered at a shallow depth there was little need to dig deeper. Some bottomed no more than ten feet below land surface, while others are more than feet deep. Though they were dug to produce groundwater many did not. Instead of abandoning a hole that took weeks to dig and trying again elsewhere, many were finished to use as cisterns. Unlike wells, cisterns do not produce water but simply store it. 5

6 Locally, dug wells which produced groundwater are referred to as living wells. Cisterns are often called wells even though they are only a storage structure. Nearly every northern and western Missouri farmstead had one or more wells or cisterns. As a result, many of the wells and cisterns that were so important a few decades ago are no longer used or needed. In fact, they are no longer an asset but a serious liability. 6

7 Abandoned large-diameter dug wells and cisterns are a very real and deadly threat to the residents of rural Missouri. When properly maintained dug wells and cisterns present little risk, but when abandoned they become potential traps, and are an unnecessary risk to human life. 7

8 Dug wells commonly are three to six feet in diameter, often larger at the bottom than at the top, and may be from ten feet to 40 feet deep. They typically produce less than three gallons of water per minute, but because of there large volume, can store several thousand gallons of water. Dug wells and cisterns still in service should have a sturdy cover, preferably made of reinforced concrete. The covers should be securely fastened, or be heavy enough to keep curious children from removing them. 8

9 Plugging the well or cistern: This well will be plugged in accordance with 10 CSR The property-owner or a contractor may perform the plugging of a hand-dug well. However if the well is over 80 feet to total depth the owner or a permitted contractor is required when plugging the well. Step 1: Remove all pumps, pipe, and debris. Step 2a: If the well contains water add the appropriate amount of chlorine. As the fill material is poured into the well, it is disinfected as it comes in contact with the chlorinated water. Step 2b: If there is no water in the well chlorine must be added to water in a sprayer. As the material is poured into the well the fill is sprayed and becomes disinfected as it comes into contact with the chlorinated water. 9

10 Push in top three feet (3') of well lining. Lining may be composed of rock, brick, or tile. Fill the well to within three feet of the surface with clean fill material such as gravel, sand, or varied size agricultural lime. Submit abandonment registration record to the division. 10

11 Bored Wells Bored wells are constructed with an auger, scoop, drag-line, or some similar machine. They are the modern equivalent of the old, hand-dug wells. These wells are relatively large-diameter, usually two to four feet, and may be feet deep, and total depth is usually at the top of bedrock. Older bored wells are commonly lined with sections of clay or tin pipe; newer bored wells are usually lined with concrete pipe. If properly constructed and covered, they can provide a satisfactory water supply and present no special hazard. Abandoned, they are as dangerous as dug wells and cisterns, and should be plugged. 11

12 Bored wells can be plugged using the same methods as those described for dug wells and cisterns. Dig around the casing and remove the top three feet (3 ) of casing. The remaining hole must be at least two feet (2 ) in diameter larger than the casing. Disinfect fill material. If there is water in the well, you must add chlorine bleach (5.25 to 6%) to the water bringing it to a concentration of at least one hundred (100) PPM. As the fill material is poured into the well, it is disinfected as it comes in contact with the chlorinated water. In agricultural or yard settings, the plug must terminate at least two feet (2 ) below the finished surface grade and the remaining hole filled with soil. In other settings, the remaining hole may be filled with clean fill if the well site is to be paved. Submit registration report form to the division. 12

13 13

14 14

15 15

16 16

17 17

18 18

19 19

20 20

21 Drilled Wells Well Cap Well Plugging Pitless Adapter If a well has been determined to present a threat to the groundwater, the Division of Environmental Quality may order the well be permanently plugged. If a well is in such a state of disrepair that continued use for purposes of obtaining ground water is impractical and which has not been in use for a period of two years or more, the division may order that the well be permanently plugged Grout Well Casing Initial Drill Hole/Casing Depth Static Water Level Pump and Pump Pipe Total Depth of Well 21

22 A site Inspection is usually conducted after Pump and any debris is removed from the well. Well is inspected to determine casing depth, Static water level, and total depth of well. These 3 facts must be determined to plug the well properly. Plugging the Well Step 1: Remove all pump pipes and debris from the well. Any liner must be removed or perforated. After the pump and any other debris has been removed from the well take an initial measurement. Be sure to note the casing depth, static water level and the total depth of the well. CASING DEPTH, STATIC WATER LEVEL, AND TOTAL DEPTH MUST BE KNOWN TO DETERMINE PLUGGING REQUIREMENTS. IF THEY CANNOT BE DETERMINED, PLUGGING INSTRUCTIONS WILL BE DETERMINED ON A CASE-BY- CASE BASIS AND MAY BE MORE STRINGENT. Casing Depth Static Water Level Total Depth of Well 22

23 Step 2: Dig around the casing deep enough to remove the top three feet (3 ) of casing. The remaining hole must be at least two feet (2 ) in diameter larger than the existing casing. Area is excavated deep enough to remove the top three feet of casing Casing Depth Static Water Level Total Depth of Well Step 3: Cut and remove the top three feet of Casing. Three feet of casing is removed. This is considered plow depth, most construction practices consider this an adequate depth. Casing Depth Static Water Level Total Depth of Well 23

24 Step 4: Disinfect fill material. If there is water in the well, you must add chlorine to the water bringing it to a concentration of at least one hundred (100) ppm. As the fill material is poured into the well, it is disinfected as it comes in contact with the chlorinated water. If there is no water in the well to be plugged, disinfect any fill material used before it is placed into the well. This can be accomplished by using a sprayer. BLEACH 1 gallon of bleach Per 100 feet of 6 inch water Column will adequately Chlorinate the fill you Add to plug your well Casing Depth Static Water Level Total Depth of Well Step 5: Fill the well from total depth of the well to fifty feet (50 ) below the bottom of the casing with clean fill such as gravel, sand, varied sized agricultural lime or other approved fill material. As clean fill is being placed into a well, periodic measurements should be taken to ensure that the fill does not reach a point closer than fifty feet (50 ) below the bottom of the existing casing. If fill is placed above this point, plugging schedules must be determined by the division and may result in removal of fill material Casing Depth Static Water Level Total Depth of Well 24

25 Step 6: As clean fill is being placed into the well, periodic measurements should be taken to ensure that the fill material does not reach a point closer that fifty feet (50 ) below the bottom of the existing casing. If fill is placed above this point, plugging schedules must be determined by the Division and may result in removal of fill material. Periodic measurements should be taken to ensure that the fill does not reach a point closer than fifty feet (50 ) below the bottom of the existing casing. If fill is placed above this point, plugging schedules must be determined by the division and may result in removal of fill material 0 10 Casing Depth Static Water Level Total Depth of Well Step 7: Place neat cement or bentonite from a point fifty feet (50 ) below the bottom of the casing to two feet (2 ) from the surface making sure the grout extends into the excavated area at least one foot (1 ) If the water level is above a point fifty feet (50 ) below the bottom of the casing, then bentonite chips must be used or the cement or bentonite slurry must be emplaced through a tremie pipe lowered through the water level to the top of the fill. Under no circumstances may cement or bentonite slurry be poured through large columns of water without the use of a tremie pipe

26 Step 8: In an agricultural or yard setting the plug must terminate two feet (2 ) below the finished surface grade and the remaining hole filled with soil. In other settings, the remaining hole may be filled with clean fill if the well site is to be paved. Soil should be mounded slightly at the top to help offset settling. Common Questions If a well is located in a well house and it has a concrete floor. If the owner wishes to fill the well to floor level. A variance from the division is required to use cement to fill the remaining hole at the level of the concrete floor. For those wells which casing depth, water level and total depth are not known and cannot be determined, plugging instructions will be determined on a case by case basis by the division and may be more stringent. Usually this will consist of the well being plugged by filling the well via tremie or pressure grouting from total depth to 2 from the surface. Neat cement is a grout, this is a 94lb mix of cement to 6 gallons of water. Concrete is not a grout. Under no circumstances may cement be poured through large columns of water without the use of a tremie pipe (well contains water that is above a point 50 feet below the bottom of the casing or liner). The well must be plugged in one continuous pour. A landowner may plug his own well as described earlier. He may contract the plugging of a hand dug or bored well less than 80 feet in total depth with any contractor. If the well is drilled or a hand dug/bored well is over 80 feet he must hire a Missouri well installation contractor or a Missouri pump installation contractor to plug the well. 26

27 Step 9: Complete and submit the Abandonment Registration Record Owner plugs well and submits Abandonment Registration Record. Registration Number is issued. 27

28 28

29 29

30 Determining Materials The quantities listed on this chart are estimates. They were estimated for a smooth bore hole. Since most wells do not have a smooth bore hole, it is suggested to add at least 10 percent or a few extra bags to the totals. Always keep a good measurement as you add the fill material. Do not go above the stated depths with the fill material. If you have 6 inch casing you need to have at least a 50- foot measurement below the casing for a grout plug. If fill is allowed to go above this point, contact the Division for directions on how to proceed. 30

31 Tony Braum Fairgrounds Rd Kodia, MO NE Sec 12/50N/23W / Phelps County Hand Dug Well (Bored) Casing Diameter 3 Feet/Cement/15 Feet Total Depth 20 Feet Static Water Level 10 Feet This information is directly from your measurements of the well: Diameter of Casing is in inches. Amount of Casing is in feet. Total Depth is in feet. Static Water Level is distance in feet from the surface. Amount of grout/grout plug needed is in feet: 31

32 Estimates of material are Listed here by type. If Neat Cement (no sand or gravel added is added) the mix is one 94lb bag to 6 gallons of water. Bentonite: There are different grades of bentonite, be sure this type is used for sealing, not food grade fill. Chips are the common type used for plugging wells. The bags are measured at 50lb. A bentonite slurry is used to plug wells usually with the use of a tremie pipe. 50lb bag mixed with gallons of water. Chlorine is a typical household bleach measured in gallons. Fill material usually consists of Gravel 1/2inch minus/ag- Lime/or Sand and can be measure in cubic yards or tons. Filling out the Abandonment Registration Record Considered the most difficult part of the task but the job is not done until the paperwork is completed. 32

33 Download at: Near the bottom of the page; 1 st form listed under Water Wells. Tony Braum Fairgrounds Rd Kodia MO Tony s Signature 1/15/10 NE X Phelps 33

34 x (Bored) x x x x x x 6.5 x x 3 x 1 1/1/10 No longer used. 34

35 Owner Signature Owner Exercises 35

36 Exercise 1 Robert Hamburger Audrain Road 140 Centralia, MO / Audrain County SE/Sec3/52N/11W Static Water Level: 9 ft Depth of Well: 17 ft Casing Diameter: 4 ft 36

37 37

38 Exercise 2 William Rebate Ballard Blvd Hardin, MO / Ray County SW Sec2/52N/26W Static Water Level: 7ft Depth of Well: 15ft Casing Diameter: 8ft 38

39 39

40 Exercise 3 Alex Leavi SR 6 Knox City, MO / Knox County SE Sec 28/62N/10W Static Water Level: 75ft Depth of Well: 100ft Casing Diameter: 12in/Depth: 100ft 40

41 41

42 Exercise 4 Peter Podickles Cordia Hollow Rd Richwoods, MO / Washington County SE Sec 1/39N/1E Static Water Level: 60ft Depth of Well: 290ft Steel Casing-Diameter: 6in/Depth: 80ft Drilled in 1958 by Wild Bill Drilling 42

43 43

44 Exercise 5 Mick Gilliam CR 1940 (Well Location: 5816 SR 17) Peace Valley, MO / Howell County NE Sec 14/25N/8W Static Water Level: 55 ft Depth of Well: 150ft Casing Depth:? Steel Drilled in October of 1969 by? 44

45 45

46 Division of Environmental Quality Wellhead Protection Section Thank You If you have any questions in the future please feel free to contact our office at (573)